A 4 yearlong study will begin next September covering 32,000 pupils at 100 schools, assessing whether a later start improves learning, performance, attainment and qualifications.

Professor of sleep medicine, Colin Espie says, “Science is telling us there are developmental changes during the teenage years, which lead to them actually not being as tired as we think they ought to be at normal bedtime and still sleepy in the morning.”

“The hormonal changes of puberty include later secretion of the hormone melatonin, which signals that it’s time to go to sleep,” said Reut Gruber, a psychiatry professor at McGill University chair of the Canadian Sleep Society’s paediatric sleep group. “The signal to get up in the morning is also later,” Gruber said.

Professor Russell Foster, director of sleep at Oxford University added to this saying getting a teenager to start their day at 7am is like an adult starting theirs at 5am.

The body clock remains in this state until the age of around 21 for males, and 19 for females.

“Later school start times for secondary grades have been shown to improve sleep-debt, punctuality, attendance, behaviour, sociability and continuous enrolment, particularly for the at-risk student population,” a review by researchers at Carleton University concluded.

There has already been evidence around the world for the promise of later school starts.

A pilot study at Monkseaton High School in North Tyneside in 2009 found that starting an hour later improved grades in core subjects by 19 per cent. Dr Paul Kelley, who now works as a research associate at Oxford University’s Sleep and Circadian Neuroscience Institute, was head teacher at the time.

“There were very positive outcomes, both academic and in terms of health,” said Kelley. “Academic results went up, illness down and the atmosphere in school changed. The students were not only much nicer to each other; they were much nicer to teachers. It was bliss. I should have done it sooner. Nothing I had ever done in all my teaching made such a difference.”

5 years ago, Toronto’s Eastern Commerce Collegiate Institute moved first period from 9 am to 10 am, giving students an extra hour to sleep in. The school, located in Toronto, Canada has been the latest starting school in North America since 2009.

The evidence for their success is undeniable – a representative for ECCI has said, “Absenteeism is down, alertness and grades are up. They (students) are relaxed and ready to learn in first period. Behaviour in class and in the hallways has also improved.”

The team at Oxford University are hoping to publish their results in 2018.